Bloated and painful stomach. Gets worst after dinner. Suggestions?

Hi. For the last week my stomach has been swollen and full of air which can be painfully at times and is mostly worse after dinner. I am finding it had to sleep I have taken things out of my diet with no change and does not to seem to be getting any better. I eat healthy 90\ of the time and have not changed the way I eat so can not work out why I am experiencing this.